feat: add solutions to lc problem: No.0217

No.0217.Contains Duplicate

Author: yanglbme

solution/0200-0299/0217.Contains Duplicate/README.md

@@ -53,10 +53,12 @@ class Solution:
 ```java
 class Solution {
     public boolean containsDuplicate(int[] nums) {
-        Set<Integer> set = new HashSet<>();
-        for (int e : nums) {
-            if (set.contains(e)) return true;
-            set.add(e);
+        Set<Integer> s = new HashSet<>();
+        for (int num : nums) {
+            if (s.contains(num)) {
+                return true;
+            }
+            s.add(num);
         }
         return false;
     }
@@ -114,6 +116,18 @@ public class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
+    return new Set(nums).size !== nums.length;
+};
+```
+
 ### **...**
 
 ```

solution/0200-0299/0217.Contains Duplicate/README_EN.md

@@ -42,10 +42,12 @@ class Solution:
 ```java
 class Solution {
     public boolean containsDuplicate(int[] nums) {
-        Set<Integer> set = new HashSet<>();
-        for (int e : nums) {
-            if (set.contains(e)) return true;
-            set.add(e);
+        Set<Integer> s = new HashSet<>();
+        for (int num : nums) {
+            if (s.contains(num)) {
+                return true;
+            }
+            s.add(num);
         }
         return false;
     }
@@ -103,6 +105,18 @@ public class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
+    return new Set(nums).size !== nums.length;
+};
+```
+
 ### **...**
 
 ```

solution/0200-0299/0217.Contains Duplicate/Solution.java

@@ -1,9 +1,11 @@
 class Solution {
     public boolean containsDuplicate(int[] nums) {
-        Set<Integer> set = new HashSet<>();
-        for (int e : nums) {
-            if (set.contains(e)) return true;
-            set.add(e);
+        Set<Integer> s = new HashSet<>();
+        for (int num : nums) {
+            if (s.contains(num)) {
+                return true;
+            }
+            s.add(num);
         }
         return false;
     }

solution/0200-0299/0217.Contains Duplicate/Solution.js

@@ -1,23 +1,7 @@
-const containsDuplicate = function (nums) {
-    let set = new Set();
-    nums.forEach(e => {
-        set.add(e);
-    });
-    return set.size !== nums.length;
-};
-var containsDuplicate2 = function (nums) {
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
     return new Set(nums).size !== nums.length;
 };
-var containsDuplicate3 = function (nums) {
-    const map = {}; // key => number, value => count
-
-    for (let i = 0; i < nums.length; i++) {
-        if (map[nums[i]] !== undefined) {
-            return true;
-        } else {
-            map[nums[i]] = 1;
-        }
-    }
-
-    return false;
-};

solution/0200-0299/0217.Contains Duplicate/Solution.py

@@ -1,3 +1,3 @@
 class Solution:
     def containsDuplicate(self, nums: List[int]) -> bool:
-        return len(nums) != len(set(nums))
+        return len(set(nums)) < len(nums)